arm64/ptrace: Avoid uninitialised struct padding in fpr_set()

BugLink: http://bugs.launchpad.net/bugs/1660993
commit aeb1f39d814b2e21e5e5706a48834bfd553d0059 upstream.

This patch adds an explicit __reserved[] field to user_fpsimd_state
to replace what was previously unnamed padding.

This ensures that data in this region are propagated across
assignment rather than being left possibly uninitialised at the
destination.

Fixes: 60ffc30d5652 ("arm64: Exception handling")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h
index 208db3df135a48d1b7118da22697ad24cd75706e..3378238b5d8ba2d66ac8202c492a28e0730f71a0 100644 (file)
--- a/arch/arm64/include/uapi/asm/ptrace.h
+++ b/arch/arm64/include/uapi/asm/ptrace.h
@@ -76,6 +76,7 @@ struct user_fpsimd_state {
        __uint128_t     vregs[32];
        __u32           fpsr;
        __u32           fpcr;
+       __u32           __reserved[2];
 };
 
 struct user_hwdebug_state {